If someone classifies something as boring, it's automatically 'bad,' at least in their opinion, is it not? Then again, 'boring' is a very broad, vague term. Boring doesn't deem something universally 'bad.' Some people could perceive plays/musicals as boring but it sure as heck doesn't make them bad by any means. Boring is technically a negative thing when it comes to entertainment, but if some people get some sort of enjoyment out of it, it's fulfilling its role as a piece of entertainment and that's all that needs to be said.